# CVE-2019-0657: Improper Input Validation in .Net Framework API's > A spoofing vulnerability in .NET Framework and Visual Studio URL parsing allows attackers to bypass security checks. - **Severity:** Medium 5.9 (`CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 6 Mar 2019 - **Updated:** 4 Aug 2024 - **Also known as:** GHSA-x5qj-9vmx-7g6g, RHSA-2019:0349 ## What is CVE-2019-0657? CVE-2019-0657 is a medium-severity vulnerability in Microsoft .Net Framework, published on 6 Mar 2019. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official description A vulnerability exists in certain .Net Framework API's and Visual Studio in the way they parse URL's, aka '.NET Framework and Visual Studio Spoofing Vulnerability'. Weakness: CWE-20 (Improper Input Validation) ## Which versions are affected by CVE-2019-0657? 6 open source packages ship an affected version, including Microsoft.NETCore.App and System.Private.Uri. It affects 4 products. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `Microsoft.NETCore.App` | NuGet | From 2.1.0 | 2.1.8 | | `Microsoft.NETCore.App` | NuGet | From 2.1.0 | 2.1.8 | | `Microsoft.NETCore.App` | NuGet | From 2.2.0 | 2.2.2 | | `Microsoft.NETCore.App` | NuGet | From 2.2.0 | 2.2.2 | | `System.Private.Uri` | NuGet | From 4.3.0 | 4.3.2 | | `System.Private.Uri` | NuGet | From 4.3.0 | 4.3.2 | | `rh-dotnetcore10-dotnetcore` | Red Hat:rhel_dotnet:1.0::el7 | All versions | 0:1.0.14-1.el7 | | `rh-dotnetcore10-dotnetcore-debuginfo` | Red Hat:rhel_dotnet:1.0::el7 | All versions | 0:1.0.14-1.el7 | | `rh-dotnetcore11-dotnetcore` | Red Hat:rhel_dotnet:1.1::el7 | All versions | 0:1.1.11-2.el7 | | `rh-dotnetcore11-dotnetcore-debuginfo` | Red Hat:rhel_dotnet:1.1::el7 | All versions | 0:1.1.11-2.el7 | | `rh-dotnet21` | Red Hat:rhel_dotnet:2.1::el7 | All versions | 0:2.1-7.el7 | | `rh-dotnet21-dotnet` | Red Hat:rhel_dotnet:2.1::el7 | All versions | 0:2.1.504-1.el7 | | `rh-dotnet21-dotnet-debuginfo` | Red Hat:rhel_dotnet:2.1::el7 | All versions | 0:2.1.504-1.el7 | | `rh-dotnet21-dotnet-host` | Red Hat:rhel_dotnet:2.1::el7 | All versions | 0:2.1.8-1.el7 | | `rh-dotnet21-dotnet-runtime-2.1` | Red Hat:rhel_dotnet:2.1::el7 | All versions | 0:2.1.8-1.el7 | | `rh-dotnet21-dotnet-sdk-2.1` | Red Hat:rhel_dotnet:2.1::el7 | All versions | 0:2.1.504-1.el7 | | `rh-dotnet21-dotnet-sdk-2.1.5xx` | Red Hat:rhel_dotnet:2.1::el7 | All versions | 0:2.1.504-1.el7 | | `rh-dotnet21-runtime` | Red Hat:rhel_dotnet:2.1::el7 | All versions | 0:2.1-7.el7 | | `rh-dotnet22` | Red Hat:rhel_dotnet:2.2::el7 | All versions | 0:2.2-3.el7 | | `rh-dotnet22-dotnet` | Red Hat:rhel_dotnet:2.2::el7 | All versions | 0:2.2.104-2.el7 | | `rh-dotnet22-dotnet-debuginfo` | Red Hat:rhel_dotnet:2.2::el7 | All versions | 0:2.2.104-2.el7 | | `rh-dotnet22-dotnet-host` | Red Hat:rhel_dotnet:2.2::el7 | All versions | 0:2.2.2-2.el7 | | `rh-dotnet22-dotnet-host-fxr-2.2` | Red Hat:rhel_dotnet:2.2::el7 | All versions | 0:2.2.2-2.el7 | | `rh-dotnet22-dotnet-runtime-2.2` | Red Hat:rhel_dotnet:2.2::el7 | All versions | 0:2.2.2-2.el7 | | `rh-dotnet22-dotnet-sdk-2.2` | Red Hat:rhel_dotnet:2.2::el7 | All versions | 0:2.2.104-2.el7 | | `rh-dotnet22-dotnet-sdk-2.2.1xx` | Red Hat:rhel_dotnet:2.2::el7 | All versions | 0:2.2.104-2.el7 | | `rh-dotnet22-runtime` | Red Hat:rhel_dotnet:2.2::el7 | All versions | 0:2.2-3.el7 | Products: Microsoft .Net Core, Microsoft .Net Framework, Microsoft Powershell Core, Microsoft Visual Studio 2017. ## How do I fix CVE-2019-0657? Upgrade Microsoft.NETCore.App to a fixed version for your release line: 2.1.8 or 2.2.2. ## Is CVE-2019-0657 being exploited? There is no known exploitation of CVE-2019-0657 in the wild and no public exploit code. ## Other vulnerabilities in Microsoft .Net Framework - [CVE-2020-1147](https://insights.sbomify.com/CVE-2020-1147/): Microsoft .NET Framework, SharePoint, and Visual Studio Remote Code Execution (high 7.8, exploited in the wild) - [CVE-2020-0605](https://insights.sbomify.com/CVE-2020-0605/): Code injection in .NET Core (high 8.8) - [CVE-2020-0606](https://insights.sbomify.com/CVE-2020-0606/): Remote code execution in Microsoft.WindowsDesktop.App.Ref (high 8.8) - [CVE-2019-1301](https://insights.sbomify.com/CVE-2019-1301/): High severity vulnerability that affects System.Management.Automation (high 7.5) - [CVE-2019-0820](https://insights.sbomify.com/CVE-2019-0820/): Regular Expression Denial of Service in System.Text.RegularExpressions (high 7.5) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2019-0657 and fix it if it is affected. What it is: CVE-2019-0657 is a medium-severity vulnerability in Microsoft .Net Framework, published on 6 Mar 2019. An attacker can exploit it over the internet without logging in, with no action from the victim. Exploitation: There is no known exploitation of CVE-2019-0657 in the wild and no public exploit code. Affected packages and fixed versions: - Microsoft.NETCore.App (NuGet): affected from 2.1.0; fixed in 2.1.8 - Microsoft.NETCore.App (NuGet): affected from 2.1.0; fixed in 2.1.8 - Microsoft.NETCore.App (NuGet): affected from 2.2.0; fixed in 2.2.2 - Microsoft.NETCore.App (NuGet): affected from 2.2.0; fixed in 2.2.2 - System.Private.Uri (NuGet): affected from 4.3.0; fixed in 4.3.2 - System.Private.Uri (NuGet): affected from 4.3.0; fixed in 4.3.2 Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2019-0657/ (Markdown: https://insights.sbomify.com/CVE-2019-0657/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2019-0657 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-0657 - OSV: https://osv.dev/vulnerability/CVE-2019-0657 --- From sbomify Insights: https://insights.sbomify.com/CVE-2019-0657/ Summaries are generated and may contain mistakes; the official description above is the record.